Internal-combustion engine.



1. DAVIDSON.

INTERNAL COMB'USTION ENGINE. APPLICATION man JULY 7. :919,

l ,3 1 '7, 356. Paented Sept. 30, 19l9.

4 SHEETS-SHEET l.

J. DAVIDSON.

INTERNAL COMBUSTION ENGiNE.

APELICATION FILED luLY 1. Isls.

www@

Egg

Pamedepa. 30,1%).

4 SHEETS-SHEET 2.

1. DAVIDSON.

[NTERNAL COMBUSTION ENGINE.

APPLICATIQN FILED JULY 7, |919.

1,317,356; Patented SeptlSO, 1919. v 4 SHEETS-SHEET 3.

| I I l @een Z021- I.. DAVIDSON.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY I9I9.

Patened Sept. 30, 1919,

4 SHEETSSHEET 4- /57 www.

i a rrr, tu

JOI-N DAVIDSON, OF MM CHESTER, ENGLAND.

INTERNALTCOMBUSTION ENGINE.

Specification of Letters Patent.

Patented Septe 30, 1919.

Application led July 7, 1919. Serial No. 309,146.

To all 'whom it may concern Be it Vknovvn that I, Jeux DAVIDSON, asubject of the King of Great Britain, residing at Manchester, in thecounty of Lancaster, England, haveinvented certain useful Improvementsin and Connected With Internal-Combustion Engines, of which thefollowing is a specification.

This `invention relates to improvements in and connected with the twocycle type of internal combustion engine described in my Britishapplication for Letters Patent No. 119,401..

The present invention has for its object to provide further embodimentsof the said type of engines and thereby increase the elli ciency andreduce the weight thereof.

The object of the invention is chieiiy to render the pumps or' said typeoi engines, double acting.

I attain these objects hy the means illus-- trated in the accompanyingtivo sheets of drawings in which, Figures l and 3 are vertical sectionsand Figs. 2 and e respectively end views of tWo cylinder enginese0nstructed in accordance with this invention.

Referring to the said figures generally, a, a are theWorking'cylinders,'c, c the charg ing cylinders and e, e the Workingpistons, f, f are the tubular extensions on the Worle ing pistons havingports g, h and forming a passage z' between the charging cylinders c, cand Working cylinders a, a to serve as mixture distributing valves.

7c are the double acting pistons of the charging pumps formed inaccordance with this invention on the said tubular extensions.

In the embodiment shown in Figs` l and 2, the cranks are arrangedopposite each other and consequently tic top side of one chargingcylinder or pump and the bottom side of the other, are used together, byformingadmissioin ports m at the top side of the left hand chargingcylinder or pump and coupling said ports together cya pipe n. By asimilar set of ports and a pipe employed in front of the engine, 2, thebottom side of the right hand charging ovlindcr or pump is coupled tothe sid l: the left hand charging cylinder or pump.

One of the charging cylial trolled at its end and the o bottom cud. hf.'the tuhular t that is to j when the charging i, one cylinder is in thetop position. the other lis in the bottom position, that position, thecharge can enter through ports l g, IL therein.

The discharge from the charging cylinder c, is also controlled. by thetubular extension f, which on the down stroke cuts ofi' communicationwith the passage and the charging cylinders c, and working cylinders a;do not come into communication With the charging cylinders until port gin the tubular extenion is opposite the port Z in the Working cylinders.

By the arrangement described both sides of the charging pistons areused, the. size of the charging pumps is considerably reduced anduselessly pumping air on the one side is avoided.

The pumps of the engine described operate as follows:-

is the pistons commence to move, a partial vacuum is created at thebottom side of the right hand and the top side of the left hand chargingcylinders or pumps, also in the ports m, m and the pipe n. This suctionis continued until the right hand piston is in a .similar position tothat shown for the left hand charging cylinder or pump, and the ports gin piston tubular extension f over run the inlet passage a2 which iscoupled to the inlet mixture pipe' when a charge is immediately drawn inand iills the bottom side of the right hand and top side of left handcharging cylinders or pumps and connecting pipe n.

On the return stroke of the pistons, the piston tubular extension ffirst closes the inlet passage .fr and the charge is then co1n pressed'until the pistons again arrive in the position shown in Fig. l, whenthe charge immediately expands into the right hand working cylinderthrough the tubular eX- tension of piston 'c and out at g.

The same order of events takes place on the top side of the right handand the bottom side oi the left hand charging cylinders or pumps iucharging the left hand 'Working' cylinder.

lt will he readily understood that in the charging pistons 7c, It asdescribed'ivith reference to Figs. 1 and 2. ln this embodiinenthowei'er, a piston valve 0 is arranged between the charging cylinders o,c actu- 5 ated vfrom the crank shaft oi,l the en gine and adjusted tocontrol the inlet p to vthe charging cylinders c, c, the top of onecharging cylinder or pump being connected like in Figs. 1 and 2, Withthe bottom of the other. l

The t0 and bottoni sides of said piston valve at R, are coupled to theinlet mixture pipe and ports'S, S are in connection with the top oftheleft hand and the bot tom of the right hand pnmp, and the bot- -tomof the left hand and the 'top of the :right hand pump.

As the right hand charging cylinder or pump piston rises from theposition shown' ton valve is 'moved downward by 1its eccentrics aridiiiin'iovers, port S'allovvi'ng a charge of mixture to be drawn. intothe under side of -the right hand and top side I ofthe left handcharging cylinder or pump. 'When the pistons reach the end of theirstroke, said piston valve will again rise and cut oli ports S. Thecharge is then coinpressedon the return stroke and delivered hrough thepiston tubular' extension f andr pots g, g to the right hand workingcylm and the left hand one descends, said pis-- minste one of saidcharging cylinders having an inlet port near its outer end and the4other having an inlet .port near its inner end; Working pistons in saidworking cylinders and arranged for simultaneous movement in reversedirections, and charging pistons connected to said Working pistons andarranged for operation in. said charging cylinders, each chargingypiston having a tubular portion; and providing a passage forA workingHuid and also having ports near its inner end and at a pointintermediate its ends.-

2. In a two-stroke cycle tivo cylinder internal combustion engine, apair of Work' ing cylinders each having an exhaust port at a pointintermediate-its ends, and a chargi ing cylinder extending from one end,one oi said charging cylinders having an inlet port near vits outer endand the other having an inlet port near its inner end; Working pistonsin said Working cylinders and arranged or simultaneous movement in lreverse directions, charging pistons connected to said 'Working pist-onsand arranged for operation in said charging cylinders, each chargingpiston having a tubular portion and providing a passage for workingfluid and also having ports iieai1 its inner end and at a pointintermediate its ends, and a Working duid iiilet'pipe each end of which.com-

